From: Charles Oliver Nutter <charles.nutter@...>
Date: 2007-07-17T15:03:16+09:00
Subject: Re: What are the semantics of to_str?

Florian Gross wrote:
> This is quite odd actually. MRI just does a respond_to?() on to_str
> here. If that returns true it actually calls <=>. This is the same way
> it handles == for all classes. (See
> http://rubyforge.org/tracker/index.php?func=detail&aid=11585&group_id=426&atid=1698
> for a request to change the == semantics.)
> 
> The thing to note here is that String#<=> doesn't use the same
> semantics as Array#<=>:
...
> I think this should be changed in MRI. Either all <=> methods should
> use to_* as an indicator without actually calling it or they should
> all call it. I'd prefer the last, because the indicator behaviour is
> somewhat unusual. (I'd like to see it changed for == as well...)
> 
> Is anyone from the MRI core team listening?

Such are the joys of implementing Ruby. I think we've got it mostly 
right in JRuby, but it took a lot of tweaking.

- Charlie